fusion_sketch_rectangle

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark this as a mutating operation, but the description adds meaningful side-effect context: it creates a new sketch on `plane` unless an existing `sketch` is supplied. It also reveals how the coordinate mode changes interpretation of (x,y), which is behavioral information beyond the schema. This goes beyond the annotation hints without contradicting them.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two tight sentences with no filler. The core action and units are front-loaded, followed by the mode semantics and the sketch/plane behavior. Every sentence adds necessary information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a moderate-complexity drawing tool, the description covers the essential calling context: units, coordinate mode, and sketch/plane selection. It does not describe return values, but there is no output schema and the primary invocation path is clear. Minor missing details like positive-dimension constraints or axis alignment are not critical for correct selection.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description carries the burden, and it does so well. It explains `mode` and the meaning of (x,y), and clarifies how `plane` and `sketch` interact. Width and height are left to name inference, but 'rectangle (mm)' supplies the unit context.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb and resource: 'Draw a rectangle (mm).' It distinguishes itself from sibling sketch tools by naming the shape and clarifying the coordinate mode behavior. The purpose is unambiguous even without inspecting the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description does not explicitly say when to prefer this tool over sibling sketch tools like fusion_sketch_circle or fusion_sketch_line, but the resource type makes the primary use case obvious. It does provide useful context for choosing between a new sketch on `plane` versus an existing `sketch`, which is indirect usage guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.